STYRENE-ASSISTED FREE-RADICAL GRAFTING OF GLYCIDYL METHACRYLATE ONTO POLYETHYLENE IN THE MELT

Glycidyl methacrylate (GMA) is a very useful monomer as it bears an ep oxy group which is capable of reacting with various other functional g roups. However, its melt free radical grafting reactivity onto a polym er backbone is low. In this study, we show that the use of styrene (St ) as a comonomer greatly promotes both GMA's grafting yield and grafti ng rate onto polyethylene (PE). It is proposed that, in the presence o f St, the dominant mechanism of the free radical grafting of GMA onto PE is that St reacts first with PE secondary macroradicals and the res ulting styryl macroradicals then copolymerize with GMA leading to graf ted GMA. We: also show that the contribution of St is not related to a n improved solubility of GMA in the molten PE. (C) 1998 John Wiley & S ons, Inc.